1. Field of the Invention
The present invention pertains to trailer fairings, and more particularly to a longitudinally and vertically adjustable trailer underbody fairing.
2. Description of the Related Art
It is known that fuel economy can be improved in the long-distance haulage of trailers by utilizing fairings mounted beneath each of the trailer""s lower, outer longitudinal edges. Ideally, such fairings extend between the rear trailer wheel assembly and the wheels of a tractor unit attached to the front of the trailer.
The trailer wheel assembly is commonly longitudinally repositioned relative to the trailer to achieve proper load distribution. If the fairing cannot be adjusted quickly and easily to accommodate repositioning of the wheel assembly, then the length of the fairing will not be optimized to reach maximum fuel economy. Hence, the length of the fairing must be reduced to ensure that the wheel assembly can be repositioned throughout its entire range without interfering with the fairing.
Prior fairing designs did not accommodate longitudinal adjustment, resulting in substantial gaps between the fairing and the wheel assembly. Such gaps reduce the fairing""s efficiency, and hence fuel economy, resulting in greater fuel costs.
Attempts to overcome this disadvantage have resulted in complex, heavy fairing assemblies that, while perhaps achieving some aerodynamic efficiency, offset the resulting fuel economy with increased weight. That, as well as the cost of manufacturing such complicated devices and a reluctance of drivers and mechanics to use such devices, have made them unfeasible. Hence, there is a need for a lightweight, low cost, easily-adjustable fairing that maximizes aerodynamic flow of air around the trailer and that is easy to use when repositioning the rear wheels in order to minimize gaps between the fairing and the wheels of the trailer and tractor unit.
The disclosed and claimed embodiments of the invention are directed to a fairing for a trailer, the trailer having an adjustable rear wheel assembly and configured for attachment to a tractor unit also having rear wheels, the fairing including a first fairing section configured for attachment to the trailer rear wheel assembly, a second fairing section configured for attachment to the trailer adjacent the front of the trailer and the rear wheels of the tractor unit and in slideable engagement with the first fairing section; and an adjustable fairing panel coupled to the first and second fairing sections, the adjustable fairing panel configured to extend and collapse as the position of the rear wheel assembly is adjusted longitudinally relative to the trailer.
In accordance with another aspect of the present invention, a fairing is provided that includes a telescopic frame having a foldable panel attached thereto. Ideally, the foldable panel includes a plurality of vertically-oriented slats slideably mounted on the telescopic frame, the plurality of slats having fabric mounted thereon. Preferably, the slats are mounted to rotate about a vertical axis to guide the foldable panel into a collapsed configuration and to facilitate extension of the panel.
In accordance with a further aspect of the present invention, the foldable panel is constructed of fabric that, ideally, is mounted under tension on the telescopic frame.
In accordance with another embodiment of the invention, a fairing for a trailer is provided having a fairing mount system that permits the fairing to move between a lowered operational configuration and an extended and raised configuration for access to the underside of the trailer. Ideally, the fairing is slideably mounted to the fairing mounts to vertically slide with respect to the fairing mounts.
As will be readily appreciated from the foregoing, the fairing of the present invention is a light-weight planar structure designed to control airflow on the lower sides of a conventional trailer, including freight box vans. The planar structure is positioned parallel to and below the sides of the trailer extending from forward of the trailer wheels to just after the tractor wheels, and it extends as close as practical to the ground. The fairing structure enables covering a variable area between the trailer and tractor wheels, which can be adjustable axially by up to as much as eleven feet.